This invention relates generally to puncture resistant packaging for meat articles having sections of protruding bone and specifically to thermoplastic packaging bags having a reinforced side adapted to confront such bone sections of a contained meat article.
In vacuum packaging of primal meat cuts having protruding bones, a problem frequently encountered concerns puncture of the packaging film by the sharp ends of such bones thereby defeating the oxygen barrier effect of the film. The term "bone puncture resistant bag" is conventionally used to refer to a thermoplastic packaging bag having a reinforced side against which are directed bone ends of a contained primal meat cut.
One approach to making a bone puncture resistant bag is to provide a reinforcing layer within the bag so that primal meat cuts may be inserted into the bag with protruding bones confronting the reinforcing sheet. An example of this approach is shown in U.S. Pat. No. 4,136,205 for "Container and Method for Packaging Meat Articles" issued Jan. 23, 1979 to Quattlebaum, wherein a mesh reinforcing sheet is heat sealed to one interior face of a thermoplastic bag to facilitate complete vacuumizing of the bag and thereby to enhance conformability of the vacuum sealed bag to a contained primal meat product.
Another approach to bag reinforcement is shown in U.S. Pat. No. 4,239,111 for "Flexible Pouch with Cross-Oriented Puncture Guard" issued Dec. 16, 1980 to Conant et al, wherein a puncture guard is bonded to an exterior face of a heat-sealable bag, the guard being composed of a plurality of oriented resin sheets which are laminated in cross-oriented relationship to each other.
An additional problem in such packaging concerns the integrity of heat seals incorporated in the manufacture of such bags. For example, either end-sealed or side-sealed bags are made by heat sealing tubular film at regular intervals, bag production from seamless tubular film being commercially advantageous. However, it is frequently a problem that these heat seals do not withstand the abuse encountered in handling vacuum packaged primal meat cuts.